<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>focus伪类选择器</title>
  <style>
    /* 把获得光标的input表单元素选取出来 */
    input:focus {
      background-color: pink;
      color: red;
    }
  </style>
</head>

<body>
  <input type="text">
  <input type="text">
  <input type="text">

</body>

</html>